1 // SPDX-License-Identifier: GPL-2.0
3 * Copyright (C) 2001 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
6 #include <linux/irqreturn.h>
8 #include <linux/sched/signal.h>
9 #include <linux/slab.h>
14 #include <kern_util.h>
17 #define LINE_BUFSIZE 4096
19 static irqreturn_t line_interrupt(int irq, void *data)
21 struct chan *chan = data;
22 struct line *line = chan->line;
25 chan_interrupt(line, irq);
31 * Returns the free space inside the ring buffer of this line.
33 * Should be called while holding line->lock (this does not modify data).
35 static int write_room(struct line *line)
39 if (line->buffer == NULL)
40 return LINE_BUFSIZE - 1;
42 /* This is for the case where the buffer is wrapped! */
43 n = line->head - line->tail;
46 n += LINE_BUFSIZE; /* The other case */
50 int line_write_room(struct tty_struct *tty)
52 struct line *line = tty->driver_data;
56 spin_lock_irqsave(&line->lock, flags);
57 room = write_room(line);
58 spin_unlock_irqrestore(&line->lock, flags);
63 int line_chars_in_buffer(struct tty_struct *tty)
65 struct line *line = tty->driver_data;
69 spin_lock_irqsave(&line->lock, flags);
70 /* write_room subtracts 1 for the needed NULL, so we readd it.*/
71 ret = LINE_BUFSIZE - (write_room(line) + 1);
72 spin_unlock_irqrestore(&line->lock, flags);
78 * This copies the content of buf into the circular buffer associated with
80 * The return value is the number of characters actually copied, i.e. the ones
81 * for which there was space: this function is not supposed to ever flush out
82 * the circular buffer.
84 * Must be called while holding line->lock!
86 static int buffer_data(struct line *line, const char *buf, int len)
90 if (line->buffer == NULL) {
91 line->buffer = kmalloc(LINE_BUFSIZE, GFP_ATOMIC);
92 if (line->buffer == NULL) {
93 printk(KERN_ERR "buffer_data - atomic allocation "
97 line->head = line->buffer;
98 line->tail = line->buffer;
101 room = write_room(line);
102 len = (len > room) ? room : len;
104 end = line->buffer + LINE_BUFSIZE - line->tail;
107 memcpy(line->tail, buf, len);
111 /* The circular buffer is wrapping */
112 memcpy(line->tail, buf, end);
114 memcpy(line->buffer, buf, len - end);
115 line->tail = line->buffer + len - end;
122 * Flushes the ring buffer to the output channels. That is, write_chan is
123 * called, passing it line->head as buffer, and an appropriate count.
125 * On exit, returns 1 when the buffer is empty,
126 * 0 when the buffer is not empty on exit,
127 * and -errno when an error occurred.
129 * Must be called while holding line->lock!*/
130 static int flush_buffer(struct line *line)
134 if ((line->buffer == NULL) || (line->head == line->tail))
137 if (line->tail < line->head) {
138 /* line->buffer + LINE_BUFSIZE is the end of the buffer! */
139 count = line->buffer + LINE_BUFSIZE - line->head;
141 n = write_chan(line->chan_out, line->head, count,
142 line->driver->write_irq);
147 * We have flushed from ->head to buffer end, now we
148 * must flush only from the beginning to ->tail.
150 line->head = line->buffer;
157 count = line->tail - line->head;
158 n = write_chan(line->chan_out, line->head, count,
159 line->driver->write_irq);
165 return line->head == line->tail;
168 void line_flush_buffer(struct tty_struct *tty)
170 struct line *line = tty->driver_data;
173 spin_lock_irqsave(&line->lock, flags);
175 spin_unlock_irqrestore(&line->lock, flags);
179 * We map both ->flush_chars and ->put_char (which go in pair) onto
180 * ->flush_buffer and ->write. Hope it's not that bad.
182 void line_flush_chars(struct tty_struct *tty)
184 line_flush_buffer(tty);
187 int line_put_char(struct tty_struct *tty, unsigned char ch)
189 return line_write(tty, &ch, sizeof(ch));
192 int line_write(struct tty_struct *tty, const unsigned char *buf, int len)
194 struct line *line = tty->driver_data;
198 spin_lock_irqsave(&line->lock, flags);
199 if (line->head != line->tail)
200 ret = buffer_data(line, buf, len);
202 n = write_chan(line->chan_out, buf, len,
203 line->driver->write_irq);
212 ret += buffer_data(line, buf + n, len);
215 spin_unlock_irqrestore(&line->lock, flags);
219 void line_set_termios(struct tty_struct *tty, struct ktermios * old)
224 void line_throttle(struct tty_struct *tty)
226 struct line *line = tty->driver_data;
228 deactivate_chan(line->chan_in, line->driver->read_irq);
232 void line_unthrottle(struct tty_struct *tty)
234 struct line *line = tty->driver_data;
237 chan_interrupt(line, line->driver->read_irq);
240 static irqreturn_t line_write_interrupt(int irq, void *data)
242 struct chan *chan = data;
243 struct line *line = chan->line;
247 * Interrupts are disabled here because genirq keep irqs disabled when
248 * calling the action handler.
251 spin_lock(&line->lock);
252 err = flush_buffer(line);
254 spin_unlock(&line->lock);
256 } else if ((err < 0) && (err != -EAGAIN)) {
257 line->head = line->buffer;
258 line->tail = line->buffer;
260 spin_unlock(&line->lock);
262 tty_port_tty_wakeup(&line->port);
267 int line_setup_irq(int fd, int input, int output, struct line *line, void *data)
269 const struct line_driver *driver = line->driver;
273 err = um_request_irq(driver->read_irq, fd, IRQ_READ,
274 line_interrupt, IRQF_SHARED,
275 driver->read_irq_name, data);
279 err = um_request_irq(driver->write_irq, fd, IRQ_WRITE,
280 line_write_interrupt, IRQF_SHARED,
281 driver->write_irq_name, data);
285 static int line_activate(struct tty_port *port, struct tty_struct *tty)
288 struct line *line = tty->driver_data;
290 ret = enable_chan(line);
295 chan_enable_winch(line->chan_out, port);
299 chan_window_size(line, &tty->winsize.ws_row,
300 &tty->winsize.ws_col);
305 static void unregister_winch(struct tty_struct *tty);
307 static void line_destruct(struct tty_port *port)
309 struct tty_struct *tty = tty_port_tty_get(port);
310 struct line *line = tty->driver_data;
313 unregister_winch(tty);
318 static const struct tty_port_operations line_port_ops = {
319 .activate = line_activate,
320 .destruct = line_destruct,
323 int line_open(struct tty_struct *tty, struct file *filp)
325 struct line *line = tty->driver_data;
327 return tty_port_open(&line->port, tty, filp);
330 int line_install(struct tty_driver *driver, struct tty_struct *tty,
335 ret = tty_standard_install(driver, tty);
339 tty->driver_data = line;
344 void line_close(struct tty_struct *tty, struct file * filp)
346 struct line *line = tty->driver_data;
348 tty_port_close(&line->port, tty, filp);
351 void line_hangup(struct tty_struct *tty)
353 struct line *line = tty->driver_data;
355 tty_port_hangup(&line->port);
358 void close_lines(struct line *lines, int nlines)
362 for(i = 0; i < nlines; i++)
363 close_chan(&lines[i]);
366 int setup_one_line(struct line *lines, int n, char *init,
367 const struct chan_opts *opts, char **error_out)
369 struct line *line = &lines[n];
370 struct tty_driver *driver = line->driver->driver;
373 if (line->port.count) {
374 *error_out = "Device is already open";
378 if (!strcmp(init, "none")) {
381 kfree(line->init_str);
382 tty_unregister_device(driver, n);
383 parse_chan_pair(NULL, line, n, opts, error_out);
387 char *new = kstrdup(init, GFP_KERNEL);
389 *error_out = "Failed to allocate memory";
393 tty_unregister_device(driver, n);
394 kfree(line->init_str);
396 line->init_str = new;
398 err = parse_chan_pair(new, line, n, opts, error_out);
400 struct device *d = tty_port_register_device(&line->port,
403 *error_out = "Failed to register device";
405 parse_chan_pair(NULL, line, n, opts, error_out);
409 line->init_str = NULL;
419 * Common setup code for both startup command line and mconsole initialization.
420 * @lines contains the array (of size @num) to modify;
421 * @init is the setup string;
422 * @error_out is an error string in the case of failure;
425 int line_setup(char **conf, unsigned int num, char **def,
426 char *init, char *name)
432 * We said con=/ssl= instead of con#=, so we are configuring all
438 unsigned n = simple_strtoul(init, &end, 0);
441 error = "Couldn't parse device number";
445 error = "Device number out of range";
453 printk(KERN_ERR "Failed to set up %s with "
454 "configuration string \"%s\" : %s\n", name, init, error);
458 int line_config(struct line *lines, unsigned int num, char *str,
459 const struct chan_opts *opts, char **error_out)
465 *error_out = "Can't configure all devices from mconsole";
469 n = simple_strtoul(str, &end, 0);
471 *error_out = "Couldn't parse device number";
475 *error_out = "Device number out of range";
479 return setup_one_line(lines, n, end, opts, error_out);
482 int line_get_config(char *name, struct line *lines, unsigned int num, char *str,
483 int size, char **error_out)
489 dev = simple_strtoul(name, &end, 0);
490 if ((*end != '\0') || (end == name)) {
491 *error_out = "line_get_config failed to parse device number";
495 if ((dev < 0) || (dev >= num)) {
496 *error_out = "device number out of range";
503 CONFIG_CHUNK(str, size, n, "none", 1);
505 struct tty_struct *tty = tty_port_tty_get(&line->port);
507 CONFIG_CHUNK(str, size, n, line->init_str, 1);
509 n = chan_config_string(line, str, size, error_out);
517 int line_id(char **str, int *start_out, int *end_out)
522 n = simple_strtoul(*str, &end, 0);
523 if ((*end != '\0') || (end == *str))
532 int line_remove(struct line *lines, unsigned int num, int n, char **error_out)
535 *error_out = "Device number out of range";
538 return setup_one_line(lines, n, "none", NULL, error_out);
541 int register_lines(struct line_driver *line_driver,
542 const struct tty_operations *ops,
543 struct line *lines, int nlines)
545 struct tty_driver *driver = alloc_tty_driver(nlines);
552 driver->driver_name = line_driver->name;
553 driver->name = line_driver->device_name;
554 driver->major = line_driver->major;
555 driver->minor_start = line_driver->minor_start;
556 driver->type = line_driver->type;
557 driver->subtype = line_driver->subtype;
558 driver->flags = TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV;
559 driver->init_termios = tty_std_termios;
561 for (i = 0; i < nlines; i++) {
562 tty_port_init(&lines[i].port);
563 lines[i].port.ops = &line_port_ops;
564 spin_lock_init(&lines[i].lock);
565 lines[i].driver = line_driver;
566 INIT_LIST_HEAD(&lines[i].chan_list);
568 tty_set_operations(driver, ops);
570 err = tty_register_driver(driver);
572 printk(KERN_ERR "register_lines : can't register %s driver\n",
574 put_tty_driver(driver);
575 for (i = 0; i < nlines; i++)
576 tty_port_destroy(&lines[i].port);
580 line_driver->driver = driver;
581 mconsole_register_dev(&line_driver->mc);
585 static DEFINE_SPINLOCK(winch_handler_lock);
586 static LIST_HEAD(winch_handlers);
589 struct list_head list;
593 struct tty_port *port;
595 struct work_struct work;
598 static void __free_winch(struct work_struct *work)
600 struct winch *winch = container_of(work, struct winch, work);
601 um_free_irq(WINCH_IRQ, winch);
603 if (winch->pid != -1)
604 os_kill_process(winch->pid, 1);
605 if (winch->stack != 0)
606 free_stack(winch->stack, 0);
610 static void free_winch(struct winch *winch)
616 list_del(&winch->list);
617 __free_winch(&winch->work);
620 static irqreturn_t winch_interrupt(int irq, void *data)
622 struct winch *winch = data;
623 struct tty_struct *tty;
631 err = generic_read(fd, &c, NULL);
633 if (err != -EAGAIN) {
635 list_del(&winch->list);
637 printk(KERN_ERR "winch_interrupt : "
638 "read failed, errno = %d\n", -err);
639 printk(KERN_ERR "fd %d is losing SIGWINCH "
640 "support\n", winch->tty_fd);
641 INIT_WORK(&winch->work, __free_winch);
642 schedule_work(&winch->work);
648 tty = tty_port_tty_get(winch->port);
650 line = tty->driver_data;
652 chan_window_size(line, &tty->winsize.ws_row,
653 &tty->winsize.ws_col);
654 pgrp = tty_get_pgrp(tty);
656 kill_pgrp(pgrp, SIGWINCH, 1);
665 void register_winch_irq(int fd, int tty_fd, int pid, struct tty_port *port,
670 winch = kmalloc(sizeof(*winch), GFP_KERNEL);
672 printk(KERN_ERR "register_winch_irq - kmalloc failed\n");
676 *winch = ((struct winch) { .list = LIST_HEAD_INIT(winch->list),
683 if (um_request_irq(WINCH_IRQ, fd, IRQ_READ, winch_interrupt,
684 IRQF_SHARED, "winch", winch) < 0) {
685 printk(KERN_ERR "register_winch_irq - failed to register "
690 spin_lock(&winch_handler_lock);
691 list_add(&winch->list, &winch_handlers);
692 spin_unlock(&winch_handler_lock);
699 os_kill_process(pid, 1);
702 free_stack(stack, 0);
705 static void unregister_winch(struct tty_struct *tty)
707 struct list_head *ele, *next;
709 struct tty_struct *wtty;
711 spin_lock(&winch_handler_lock);
713 list_for_each_safe(ele, next, &winch_handlers) {
714 winch = list_entry(ele, struct winch, list);
715 wtty = tty_port_tty_get(winch->port);
722 spin_unlock(&winch_handler_lock);
725 static void winch_cleanup(void)
727 struct list_head *ele, *next;
730 spin_lock(&winch_handler_lock);
732 list_for_each_safe(ele, next, &winch_handlers) {
733 winch = list_entry(ele, struct winch, list);
737 spin_unlock(&winch_handler_lock);
739 __uml_exitcall(winch_cleanup);
741 char *add_xterm_umid(char *base)
750 len = strlen(base) + strlen(" ()") + strlen(umid) + 1;
751 title = kmalloc(len, GFP_KERNEL);
753 printk(KERN_ERR "Failed to allocate buffer for xterm title\n");
757 snprintf(title, len, "%s (%s)", base, umid);